/**
 * Diagram editor — rotate helpers.
 * Node.rotation is around the local origin (top-left). These helpers keep the
 * visual center fixed when the angle changes so symbols spin in place.
 */
export declare function normalizeDegrees(deg: number): number;
export declare function snapDegrees(deg: number, step?: number): number;
/** Angle in degrees from center to pointer (0° = east, 90° = south — canvas Y-down). */
export declare function pointerAngleDegrees(cx: number, cy: number, px: number, py: number): number;
/** Parent-space center of a card given top-left origin + rotation (degrees). */
export declare function rotatedCardCenter(x: number, y: number, width: number, height: number, rotationDeg: number): {
    x: number;
    y: number;
};
/**
 * Set node.rotation while keeping the card's visual center fixed.
 * `width` / `height` are the unrotated card size including current scale.
 */
export declare function setRotationAroundCenter(node: {
    x: number;
    y: number;
    rotation: number;
    markDirty?: () => void;
}, nextDeg: number, width: number, height: number): void;